Documents are most commonly executed as simple contracts. A contract is made binding on the date that both parties intend that it is to come into effect, which is typically evidenced by both parties signing the agreement. There is no requirement for the signature to be witnessed. Simple contracts have a statutory limitation period of six years.
The number of calories in a food is a measure of how much potential energy that food possesses. A gram of carbohydrates has 4 calories, a gram of protein has 4 calories, and a gram of fat has 9 calories. Foods are a compilation of these three building blocks. So if you know how many carbohydrates, fats and proteins are in any given food, you know how many calories, or how much energy, that food contains.
Of these six nutrients, carbohydrates, protein and fats provide calories. Each gram of carbohydrate and protein yield 4 calories/gram. Each gram of fat yields 9 calories. A calorie is a measurement, just like a teaspoon or an inch. Calories are the amount of energy released when your body breaks down (digests and absorbs) food.